The velocity and attenuation of an ultrasonic longitudinal wave for
nano-scaled copper are determined by a laser ultrasonic technique. The
nano-scaled copper samples are composed of super fine particles 10-nm in size,
and are prepared by a suppressing and sintering technique under a vacuum, and
different pressures are used in the experiment. These samples are of thicknesses
between 125--300 (mu)m. The experimental results show that the velocity
dispersions and attenuation spectra of nano-scaled copper depend on their
fabrication technology conditions, which are different from those of
conventional Cu. The attenuation of nano-scaled copper is proportional to the
frequency of ultrasound, and some absorption peaks appear at the curves of
attenuation versus frequency, but the attenuation of conventional Cu is
proportional to the square of the frequency. The velocity of nano-scaled copper
is lower than that of conventional Cu. The experimental system, measurement
method, results, analyses and discussions are also presented.